Influence of Multiple Recycling Processes on the Properties of MgO Derived from Magnesium Oxychloride (MOC)

Magnesium oxychloride is gaining renewed attention in the scientific community as a light-weight and low-carbon mineral binder. However, primary production pathways are constrained by geographically concentrated availability of MgCO3 and its energy-intensive calcination at temperatures up to 1000 °C. In this regard, reclaiming MgO from waste MOC through calcination at up to 1000 °C has been demonstrated to produce high quality MgO without decarbonation involved. In prior work by the authors, thermal recycling of MOC between 400 and 700 °C has been investigated and a lower temperature boundary of 550 °C has been established at which recycled MgO yielded highest reactivity and fully recycled MOC achieved 90% of the mechanical performance of the reference mix.